Armed with two single shot pistols, one or more of Colt's Patterson revolvers, a rifle and a large Bowie knife, the men of "Hays' Mounted Texas Volunteers" commanded the respect of friends and enemies alike. Commanded by John Coffee "Jack" Hays they distinguished themselves at the Battle of Monterey and during subsequent anti-guerrilla operations in which they excelled. Both intrepid and ruthless in battle they were soon branded "Los Diablo Tejanos" by their Mexican foes.